Discover x402 services

One public endpoint to discover x402 services that accept USDC, across many blockchains. No API key, no account.

GET /v2/x402/discovery/resources

List marketplace resources

cURL

curl --request GET \
  --url https://api.circle.com/v2/x402/discovery/resources

200

{
  "x402Version": 2,
  "items": [
    {
      "resource": "https://api.aisa.one/apis/v2/coingecko/simple/price",
      "type": "http",
      "x402Version": 2,
      "lastUpdated": "2026-06-25T16:40:14.015Z",
      "accepts": [
        {
          "scheme": "exact",
          "network": "eip155:8453",
          "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
          "amount": "10000",
          "payTo": "0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed",
          "extra": {
            "name": "USD Coin",
            "version": "2"
          }
        }
      ],
      "metadata": {
        "provider": {
          "name": "AIsa API",
          "description": "cryptocurrency market data prices",
          "category": "FINANCIAL_ANALYSIS",
          "tags": [
            "x402",
            "crypto",
            "market-data"
          ],
          "website": "https://aisa.one",
          "docsUrl": "https://aisa.one/docs/api-reference",
          "openApiUrl": "https://aisa.one/openapi.yaml"
        },
        "path": "/apis/v2/coingecko/simple/price",
        "method": "GET",
        "description": "Get cryptocurrency prices in multiple currencies",
        "mimeType": "application/json",
        "input": {
          "type": "object",
          "properties": {
            "ids": {
              "type": "string"
            }
          }
        },
        "output": {
          "type": "object"
        },
        "siwx": false,
        "supportsVanillax402": true,
        "supportsCircleGateway": true
      }
    }
  ],
  "pagination": {
    "limit": 50,
    "offset": 0,
    "total": 636
  }
}

Categories

Every listing is classified with one category in metadata.provider.category. Filter on it with the category query parameter to narrow results to a domain.

Category	Description
SOCIAL_INTELLIGENCE	Social platform data and audience or sentiment signals.
FINANCIAL_ANALYSIS	Market data, prices, and financial analytics.
WEB_SEARCH_RESEARCH	Web search, scraping, and research retrieval.
PREDICTION_MARKETS	Odds, forecasts, and prediction-market data.
CREATIVE	Media generation such as images, audio, and text.
INFRASTRUCTURE	Developer tooling and infrastructure utilities.

Paying for a service

Discovery tells you what each service accepts. To actually pay, use one of two rails:

• Vanilla x402: a signed onchain USDC transfer that any USDC wallet, including a centralized custodial one, can produce.
• Circle Gateway: offchain, batched settlement for gasless, sub-cent payments.

Each listing’s accepts[] and its supportsVanillax402 and supportsCircleGateway flags tell you which rails it takes. To pay from Circle CLI, see Pay for a service. For the concepts and buyer integration, see Agent nanopayments.

To find services payable on a specific blockchain, filter with the structured network parameter, not the query text field. query matches free text (URLs, providers, descriptions, tags), so it does not reliably match a chain.

Related

• Service catalog
• OpenAPI spec
• A2A card
• Agent skills index (llms.txt)

Query Parameters

query · string

Fuzzy search across resource URLs, providers, descriptions, and tags.

Example:

"weather"

type · enum<string>

Protocol type.

Available options: http, mcp

Example:

"http"

category · enum<string>

Service category. One of SOCIAL_INTELLIGENCE, FINANCIAL_ANALYSIS, WEB_SEARCH_RESEARCH, PREDICTION_MARKETS, CREATIVE, or INFRASTRUCTURE.

Available options: SOCIAL_INTELLIGENCE, FINANCIAL_ANALYSIS, WEB_SEARCH_RESEARCH, PREDICTION_MARKETS, CREATIVE, INFRASTRUCTURE

Example:

"FINANCIAL_ANALYSIS"

network · string

CAIP-2 identifier (for example, eip155:8453) or a legacy SDK name (for example, base, base-sepolia). Only EVM chains have legacy aliases; Solana must use its full CAIP-2 identifier.

Example:

"eip155:8453"

asset · string

Payment token contract address.

Example:

"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"

scheme · string

Payment scheme (for example, exact).

Example:

"exact"

payTo · string

Merchant (seller) wallet address.

Example:

"0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed"

maxUsdPrice · number

Maximum price per request in USD (for example, 0.01).

Example:

0.01

supportsVanillax402 · boolean

When true, returns only endpoints that support vanilla x402 (onchain payments).

Example:

true

supportsCircleGateway · boolean

When true, returns only endpoints that support Circle Gateway (offchain, batched payments).

Example:

true

siwx · boolean

When true, returns only SIWX (Sign-In With X, browser-auth) endpoints; when false, excludes them; omit to return all. Use false for CLI or automation.

Example:

false

fields · string

Comma-separated list of fields to include in each item.

Example:

"resource,type,metadata.provider.name"

limit · integer · default: 50

Number of items to return. Default 50, maximum 200.

Required range: 1 <= x <= 200

Example:

50

offset · integer · default: 0

Number of items to skip, for pagination. Default 0.

Required range: x >= 0

Example:

0

Response

200 - application/json

A paginated list of x402-compatible service listings.

x402Version · integer

The x402 protocol version the response follows.

Example:

2

items · object[]

Array of service listings.

Show child attributes

pagination · object

Pagination metadata for the response.

Show child attributes